1. Field of the Invention
The present invention generally relates to sensors, especially an optical gas concentration sensor.
2. Description of the Prior Art
Blood analyzers help patients manage their own health conditions in a more cost-effective and convenient way before seeking a doctor for further diagnosis and treatment. Not only can patients monitor their health conditions by checking the densities of eight major parameters whenever they wish, but the information can also be provided to the doctors to facilitate diagnosis. When measuring the concentration of carbon dioxide, sensors that can provide stable and continuous measurements are needed.
Conventional electrodes for sensing the concentration of carbon dioxide, for example a biomedical sensing system called i-STAT® available from Abbott Laboratories, U.S.A., are very accurate but expensive. Moreover, there are problems such as gas content in blood may be consumed during measurement and their size being large, making them unsuitable for continuous intrusion-type measurements. Since the size of the overall sensing system is usually bulky, they are not suitable for home care use, and may cause discomfort to users. Mobility and accuracy in measurement are also affected. Therefore, there is a need for an improved design that simplifies its structure and enhances its operating comfort.